In many applications which process signals in a telephone communications environment, there is a need to deal with digital telephone signals in a time-division multiplexed (TDM) data format. As is well known to those of ordinary skill in the art, such signals are comprised of several individual channels, each of which contains information. Further, it is well known that there is a need for apparatus which will receive such a TDM signal and be able to access information in various individual channels and to insert information into the various individual channels. Still further, it is well known that there is a need for such accessing and inserting information to be performed on the same signal by a multiplicity of apparatus.
As is well known to those of ordinary skill in the art, one method and apparatus for accomplishing the above-described multiple access to a data stream is a data bus wherein the data stream is made available to a multiplicity of apparatus for accessing and inserting information in accordance with predetermined bus protocols.
Presently known TDM bus architectures are complicated and the required extraction of TDM timing and control signals from the data streams carried on these buses for identifying the various channels requires substantial and often complex hardware. In light of this, there is a need in the art for a TDM bus: (a) which permits a multiplicity of apparatus to monitor a single TDM signal simultaneously and (b) wherein the various timing and control signals are provided in a manner that minimizes the hardware needed by the apparatus for identifying the various channels for accessing and inserting information therein.